re-seasoning & maintaining seasoning on cast iron

here's a "procedure" that i've come up with for re-seasoning and maintaining the seasoning on cast iron. from what i can see, it is well-grounded and should serve anyone in any situation. many thanks to members daikon and rod franklin for their contributions to this procedure:

a) if re-seasoning is necessary, start with a pan that is stripped down to the bare metal and good as new. to achieve this, run the pan(s) through the self-cleaning cycle of your oven. it seems to help to pre-heat the oven first to 500 degrees for 15 minutes or so, making sure the pans get hot as well. the first time i tried, it seemed as though the pans never got the chance to heat up, since they started out cold, and it looked like none of the seasoning or crud had been removed. the second time, i pre-heated everything and this resulted in pans that were completely stripped down to the bare metal, ready for the re-application of seasoning. if your oven doesn't self clean, then you can accomplish much the same thing by putting your pan in a decent-power gas grill at full-blast for about an hour.

b) allow the pans to cool until they are warm, then inspect them and wipe away any ash, crud, etc. with a wet (or oiled) cloth or paper towel, and allow them to completely dry and finish cooling before re-seasoning. if there is any "orangish" tint, give it a vigorous wiping with an oiled paper towel or cloth until it is gone. if it persists, use a wire brush to eliminate it.

c) wash in hot water with no soap and allow to dry, setting it on the stovetop a few minutes if necessary to eliminate any moisture and ensure that it is completely dry. you are now ready to re-season.

re-seasoning:

a) start with a "warm" pan - i've been heating them in a 200-degree oven if necessary. i am guessing that this serves to open up the pores (or something along those lines) and make the pan more receptive to the oils for seasoning.

b) use an oil with a low smoking point, not a high smoking point. before, i had used canola oil, which has a high smoking point, but the reading i've done suggests that, for reasons stated below, lower is probably better. the best-rated oil to use according to the article i read is (food-grade) flaxseed oil, which has a very low smoking point relative to the others that are commonly used. but flaxseed oil isn't the only optioni used cooking spray that was 100% olive oil, and had very adequate results.

c) apply a very light coating to all surfaces, then wipe it off to the point where only a fine "sheen" is left. this is all you need, and any more is excessive and causes drips etc. the point is to build layers, like a glaze on barbecued ribs, one light coat at a time.

d) heat the pan to 350 degrees, and allow it to maintain this high temperature until its "smoking point" has been reached and then has exhausted itself and it quits smoking. this might take about an hour, maybe a little more. my reading shows two reasons for this. i don't know all of the science behind it, but my understanding is that while it is at (or exceeding) its smoking point, the oils are undergoing polymerization, which results in the seasoning we are trying to achieve, protecting the pan from rust and building a good "non-stick" surface. the other reason is that evidently, there is some concern of possible carcinogens in the smoke, and heating the pan beyond that point, until it is done smoking, evidently eliminates any possiblity of "smoke carcinogens" in food. so in other words, smoke on a cast iron pan is evidently good when making seasoning, but bad for cooking? just a guess there, but it dovetails with my reading. my guess is that the risk is small, but i can't say for sure, so no need to take chances.

e) shut off the oven and allow the cast iron to cool naturally, then repeat as necessary. you are looking for the pan to go from the greyish, silvery colour at the start, to a deep, consistent, nearly-black finish, with the texture of the pan being clear and uncompromised. after watching the progression of seasoning "layers" during this experience, i definitely think that six seasoning sessions are a good "minimum" for re-seasoning and that this procedure is golden, if one takes the time to do it.

maintaining the seasoning on your cast iron:

a) use plenty of hot water and only ever use soap or an abrasive pad if absolutely necessary. shake off the water and then put the pan on the stove over medium heat or in a hot oven until any remaining water drops have boiled away and the pan even starts to smoke a little. then, if it looks like it needs it, coat lightly with oil or cooking spray, then wipe it down, while the pan is still hot and let it finish cooling.

if anyone has any questions or anything to add to this, feel free to post here. my writing here is based partly on reading and partly on observation when trying this, and is of course subject to correction; however the results i have seen so far seem to be very effective.